08 September 2015
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Early detection of refrigerant leaks has never been so important.
Peter Dinnage, Technical Director at Climalife explains why you should take leak detection seriously.
Whether it’s for safety due to flammability or to maintain optimum energy efficiency, minimise the cost of the refrigerant lost, or to comply with legislation such F-Gas, there has never been so many compelling reasons to find leaks and fix them early and quickly.
With the cost of a basic automatic leak detection system little more than the price of a 60kg bottle of refrigerant, and with the higher GWP refrigerants predicted to dramatically increase in price over the next few years, it would seem a shrewd investment and one that would help users to comply with the new revised F-Gas legislation.
Peter Dinnage, Technical Director at Climalife explains why you should take leak detection seriously.
Whether it’s for safety due to flammability or to maintain optimum energy efficiency, minimise the cost of the refrigerant lost, or to comply with legislation such F-Gas, there has never been so many compelling reasons to find leaks and fix them early and quickly.
With the cost of a basic automatic leak detection system little more than the price of a 60kg bottle of refrigerant, and with the higher GWP refrigerants predicted to dramatically increase in price over the next few years, it would seem a shrewd investment and one that would help users to comply with the new revised F-Gas legislation.
The legislation surrounding leak detection
The revised F-Gas 517/2014 legislation came into effect on 1st January 2015 placing greater importance on minimising refrigerant emissions and requiring more regular leak checks on many types of equipment.
Article 3 requires operators of equipment containing F-Gases to take precautions to prevent leakage and take all measures, technically and economically feasible, to minimise leaks.
Furthermore they have to ensure equipment is repaired without undue delay. Many of the principles of the 2006 F-Gas legislation remain in Articles 4 and 5, but equipment with higher GWP refrigerants will need to be checked for leaks much more frequently.
The refrigerant charge is no longer the reference point, instead it’s the CO2 Tonnes equivalent charge value. This is calculated by multiplying the charge in kg by the GWP value of the refrigerant in the system.
Article 3 requires operators of equipment containing F-Gases to take precautions to prevent leakage and take all measures, technically and economically feasible, to minimise leaks.
Furthermore they have to ensure equipment is repaired without undue delay. Many of the principles of the 2006 F-Gas legislation remain in Articles 4 and 5, but equipment with higher GWP refrigerants will need to be checked for leaks much more frequently.
The refrigerant charge is no longer the reference point, instead it’s the CO2 Tonnes equivalent charge value. This is calculated by multiplying the charge in kg by the GWP value of the refrigerant in the system.
CO2 Tonnes equivalent value = Refrigerant charge in kg x GWP value of the refrigerant /1000
- Any equipment containing 5 Tonnes CO2 equivalent or more needs to be leak checked and documented, as required by Article 6 on record keeping.
- For R-404A this is reduced to 1.3kg charge, R-410A to 2.4kg, although R-134a has increased to 3.5kg.
- For hermetically sealed systems the threshold doubled as it applies from 10 Tonnes CO2 equivalent.
- For systems with a charge of 3kg or less (6kg for hermetic systems), the leak check requirements don’t apply until 1st January 2017.
- For all other systems the new requirements are already in force.
The frequency of leak checking is dependent upon the CO2 Tonnes equivalent value, with thresholds also at 50 and 500 Tonnes CO2 equivalent.
Those systems with automatic leak detection that alerts the operator do not need to carry out a leak check as frequently. The logic being that if a leak were to occur, fixed leak detection would identify it immediately rather than waiting until the mandatory leak check.
For systems with 500 Tonnes CO2 equivalent or more, fixed leak detection is mandatory. For R-404A this applies to anything with a charge of 127kg or more, whilst for R-407C it would be 282kg.
Those systems with automatic leak detection that alerts the operator do not need to carry out a leak check as frequently. The logic being that if a leak were to occur, fixed leak detection would identify it immediately rather than waiting until the mandatory leak check.
For systems with 500 Tonnes CO2 equivalent or more, fixed leak detection is mandatory. For R-404A this applies to anything with a charge of 127kg or more, whilst for R-407C it would be 282kg.
The incentive for fixed leak detection is to minimise emissions and early detection of a leak starting to occur, which for high GWP refrigerants is particularly important.
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Useful tools are available, such as the F-Gas Solutions app from Climalife, which can advise GWP levels and calculate the CO2 equivalent tonnage for all common refrigerants
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5 key benefits of installing a refrigerant leak detection system
- Safety – monitor refrigerant leakage to avoid harming people and protect assets.
- Efficiency – leaks reduce energy efficiency and may increase wear and tear.
- Cost savings – reduce the amount of refrigerant being used.
- Environmental – reduce the amount of refrigerants released to atmosphere
- Compliance – EN 378, EN 14624 and F-GAS.
Leak detection: systems and sensors
Leak detection systems
There are several different types of leak detection systems available using different sensing technologies. Point detectors have a sensor which is mounted at the probable point of a leak and have the advantage that every instrument continuously monitors the air at that location, resulting in much shorter response time.
Aspirated systems sample gas via tubing from various locations to a central sensor and act as a complete centralised control system where the sampled air is evaluated within the system and all measure values are displayed in one unit.
Aspirated systems sample gas via tubing from various locations to a central sensor and act as a complete centralised control system where the sampled air is evaluated within the system and all measure values are displayed in one unit.
Leak detection sensors
There are a number of different sensor technologies available for use in refrigerant leak detection systems. Semiconductor sensors (suited to HFCs, CFCs, HCFCs and propane) respond to a broad range of gases and are usually a lower cost option. Infrared sensors (suited to HFC, CFC, HCFCs, NH3 and CO2) and Electrochemical sensors (suited to NH3) are more gas-specific types and provide higher performance, enhanced accuracy and smaller detection limits.
How and where should you monitor?
Chiller plants, refrigeration plants, cold stores and store floors should be monitored, so too should air conditioning systems to ensure building occupant safety. There are a number of companies in the UK, such as Climalife working in partnership with Bacharach, who can advise on various leak detection solutions for a range of building needs and provide more tailored guidance around location of equipment, type and number of sensors to use.
Leak Detection is here to stay
To meet the F-Gas quota reductions on the amount of refrigerant that can placed on the market each year, fixed leak detection is going to play an important part in reducing leaks and will be very cost effective as refrigerant prices escalate, particularly those with higher GWP values.
